Absolute permissive block-signaling system



S. N. WIGHT.

ABSOLUTE PERMISSIVE BLOCKSIGNALING SYSTEM.

APPLICATION FILED APR. 28. I916.

Patented Nov. 25, 1919;

g IYAH/ENTOR. U 2' W Z m VVVVV V AUOR/VEY SEDGWICK N. WIGHT, OF ROCHESTER, NEW YORK,'ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, OF GATES, NEW YORK, A COREORATION OF NEW YORK.

ABSOLUTE PERMISSIVE BIiOCK-SIGNALING SYSTEM.

Specification of Letters Patent.

Patented Nov. 25, 1919.

Application filed Apr-i128, 1916. Serial m. 94,171.

To all whom it may concern:

Be it known that I, SEDGWICK N. WIGHT, a citizen of the United States, and a resident of the city of Rochester, in the county of Monroe and State of New York, have invented a new and useful Improvement in Absolute Permissive Block-Signaling Systems, of which the following is a specification.

This invention relates to signaling systems for single track railroads, and more particularly to such signaling systeins of the type commonly called absolute permissive block signaling systems, and disclosed in my Patent No. 1,294,736, Feb. 18, 1919.

The primary object of this invention is to devise an absolute permissive block signaling system in which electrical energy derived from a single source may be used for operating some or all of the signals and their associated controlling devices, and in which temporary interruptions of the current supplied from said single source will not affect the proper operation of the signaling system.

A further object of the invention is to' accomplish the above mentioned object in a simple and reliable manner without the use of additional relays or other operating parts and without the use of complicated apparatus.

Other objects and advantages will appear as the description of the invention progresses, and the novel features of the invention will be particularly pointed out in the appended claims. 7

In describing the invention in detail reference is had to the accompanying drawing in which is illustrated a preferred physical embodiment of the invention, in which like reference characters designate like parts in the several views, and in which:

Figure 1 is a diagrammatic view showing a portion of a railroad track and signals for governing traffic over said portion of track, together with the controlling devices for governing these signals and the electrical connections constituting the operating and controlling circuits; and,

Fig. 2 is'a fragmentary view showing one way in which one contact finger ofa relay may be made to lag behind the operation of the other contact fingers of that same relay, this or a similar modification of the ordinary construction of .a track relay being used in the absolute permissive block signaling system embodying this invention.

Since a system for governing the movements of trains over a stretch. of single track having passing sidings at intervals is shown in detail and fully described in my prior application above mentioned, there is illustrated in the accompanying drawing for simplicity, only a part of the complete sys term, which is, however, suflicient to enable a clear understanding of the construction and operation of the improvement embodying this invention; and since the control'of the various signals used in a complete absolute permissive block signal system is clearly shown and described at length in my prior application above mentioned, the controlling circuits shown in the accompanying drawing have been simplified by omitting the construction and arrangement of parts and the controlling circuits which give the fortyfive degree or caution position of the signals.

In the accompanying drawing, numerals 1 and 2 designate a portion or stretch of single track which is. divided into track sections of suitable length by insulating joints 3, there being shown two complete track sections, designated B and C and the adjacent ends of two other track sections designated A and D. Traific over the stretch of track illustrated may be in either direction, either from left to right, as indicated by the arrow X, or from right to left as indicated by the arrow Y. Located at the left hand end of the track section B is a signal 4 for governing trafic in the. direction indi ,cated by the arrow X,'and at the left hand end of the track section D is another signal 5 for governing traffic in the same direction. Located at the right hand end of the track section C is a signal 7 for governing trafiic in the direction indicated by the arrow Y,

and located at the right hand end of the track section A is another signal 6 for governing traffic in the same direction. Since the improvement embodying this invention has to deal more with the controlling circuits for the signals 4: and 7 governing traffie in opposite directions over the track sections B and C, and commonly termed opposing signals, only the controlling devices andcircuit associated withthese signals 4 land 7 are illustrated; but itshould beunderstood that the controlling devices and circuits for the signal 5 are the same as those for the signal 4 and'in the same way the controlling circuits and devices associated with the signal 6 are the sameas those associated with the signal 7 The signals 4,.

5, 6 and 7 may be any oneof the well'known and approved types used at the present day either in single track signaling systems or double track signaling systems, and in the particular embodiment of the invention illustrated, the signals are of the well known semaphore type and in. general consist of an operating motor for moving the semaphore arm from a horizontal or biased position, which may be termed a stop or vdangerposition, to an operated position or positions,

which may indicate clear or caution, together'with suitable means forretainingthe semaphore arm? in its operated position 'or positions. I n'theparticular embodiment of the invention illustrated, the semaphores have only two positions-namely, a horizontal orstop position, and a verticalorclear position; but it should be understood that Cor modification to signal systems in which two LtWO-POSIGIQII signals arranged as home and distant signals are employed, or to signaling systems in'which signals of any suitableitype are used. 'Thisinvention-has been shown in connection with the controlling circuits: and'devices for signals commonly termed intermediate signals, which control traflic along astretch or portion of single 1 track between two passing sidings; and as explained atlength in my prior application above mei'itioned, these signals 4 to 7 inclusive, are of the type commonly known as 'permissive'signals; but since thecharactersacs Of tlllg type of signal are well known in the art,'it is deemed unnecessaryto fur-' ther discuss the significance of these signalsor describe in detail how thesignals are constructed'so as to enable the engineer to differentiate'betwe'en them as permissive signails and other signals along the railroad.

The improvement embodying this invention 'isfmore especially concerned with signaling systems in which some. or all of the signals and their-controlling devices are supplied with current from a singlesource; and as aniillustration of this type of signal- .ing systemthere is shown in theaccompanying drawing asuitable alternating current generatorS connected to line wires 9 and '10, which are carried on poles or 1n any: other suitable'way along the portion of the railroadtrackwhich is signaled. Opposite the v adjacent endsof the tracksections .B and C is located a tracktransformer l1,"the prima ryof which is connected in the usual way "across the line wires 9 and 10." The secondary of the transformer 11 is provided -withtwo windings 12 and 13, which are connected in the usual Way'across the track rails [land 2 at the ends of the track sections B and C, respectively. At the right hand end of the track section/A a track relay 14, of

suitable construction and capable of being operatediby alternating current, is connected in-the usual'wayacrossthe track rails 1 and 2 of said track section; and in a like man'- n'ertrackrelays 15, 16 and 17 are connected to the tracksections B, C and D. These track "relays are provided 'with' armatures or contact fingers which are illustrated conventionally and are. given, for convenience,

the same reference characters as the comesponding relay with a distinctive exponent I added thereto. Wh ile these track relays may be, as stated, of any suitable construction, one contact finger of each relay is so arranged or-constructedasito lag behind the operation of the other'contact fingers of the relay, when that relay is energized or picked up. Thisllagging operation of onecon'tact finger'of each 'track relay may be obtained in different ways, 'and'may 'result'from' a special construction of the relay itself or from a special attachment or controlling means for one of the contact {fingers of the relay;' One 511111316' arrangement and con- 'struction capable'of performing the functions necessary for use in the system'embodying this invention is shown in Fig. 2,

and is morefully described hereinafter.

Associated with each of'the signals 4, 5, 6 and 7 is a relayhereinafter termed a line rela ,therelays'for the signals4an'd 7 only being shown-and beingdesignated 18 and 19. Also associated with each of the signals 4 to 7, inclusive, is a relay hereinaftenter'med a stick relay, the stick relays associated with the signals 4 and 7 only being shown, and be ing designatedQO. and 21. The armatures or contact fingers of the line relays 18and 19 and the stick relays 20 and21 are shown a0 cording to established convention and are given the same reference characters as the corresponding relay with distinctive expo-v nents added thereto. Associated with the signals at and 6 is a transformer Tflhavihg its primary connected across the line'wires 9 and 10 and having a secondary 22 connected by conductors to the various conductors and circuits-used for controlling the relays and the semaphore operating mechanism for said signals 4c and 6, and in a similar way the transformer T having the secondary 23 is associated with'the signals'5'a-nd '7 As soc'iated with each of the' signals 4 to 7,

inclusive, is a circuit controller -whichisrepresented according to established convention, and which is operatively connected to the corresponding semaphore or semaphore operating mechanism, only the circuit controllers associated with the signals l and 7 being shown and being designated 24, and 25. These circuit controllers 24: and 25 are closed when the corresponding semaphores occupy the vertical position or the diagonal position, or any position between the vertical position and the diagonal position, the exact extent of the angular movement'of the semaphore during which the circuit controller is closed being dependent upon the operating characteristics of the semaphore and its con trolling relays, as will be made more clear hereinafter.

Although certain relays are herein designated track relays, certain others as line relays, and certain others as stick relays, these designations are chosen for the sake of con venience in description; and it should be understood that there is ordinarily in practice no essential difierence in the construction of the relays so designated, with the possible exception of the track relays, each of which, as explained hereinbefore, has one contact finger which lags in its movement behind the movement of the other contact fingers when that track relay is picked up. Each of the relays above mentioned are preferably designed to be operated by alternating current in a way which will be clearly under stood by those skilled in the art of railway signaling.

Extending the length of the railroad track protected by the signaling system is a common wire designated 26, and which, as will be readily understood by those skilled in the art of railway signaling, constitutes a common conductor for circuits connecting the different signal locations.

The operation of the signaling system disclosed in my prior application above mentioned is set forth at length in said ap plication, and in order to obtain a clear understanding of the improvement embodying this invention, it will be necessary to re for to the operation of this system as a whole only briefly. Generally stated the operation of the system disclosed in my prior application is such that when a train is traveling over the stretch of single track between passing sidings in one direction, as for instance, in the direction indicated by the arrow X, the opposing signals governing trafiic in the opposite direction, as the signals 6 and 7, are all caused to assume their biased or stop position, thereby blocking the opposing movement of trains, while signals governing traffic in the direction in which the train is traveling, as the signals 4 and 5, are allowed to move successively first to their forty-five degree or caution position, and then to their ninety degree or full proceed controlling the line relay of the next position as the train advances. As fully shown and described in my prior application this control of the signals is obtained by the use of line relays each of which is controlled by the line relay associated with the next signal in advance governing tra'liic in the same direction as well as by the track relays of the track sections protected by the corresponding signal; and by arranging a stick relay such that this stick relay at a signal will be energized when a train passes that signal and is moving in the direction of traflic governed thereby, and such that this stick relay when energized will prevent the line relay of the corresponding signal from signal in the rear. The controlling circuits of the line relays are not shown in their entirety in the accompanying drawing, since this drawing, as explained hereinbefore, shows only part of the signaling system, but since the control of the line relay 18 associated with the signal 4 is the same as that of the line relay (not shown) associated with the signal (not shown) located at the left of the signal l, the complete circuit for controlling the line relay 18 may be readily determined as follows:

Commencing at the common wire 26, conductors 27, 28 and 29, line relay 18, conductor 30, armature 15 of the track relay 15 in its upper position, conductor 31, armature 16 of the track relay 16 in its upper position, conductor 32, armature 21 of the stick relay 21 in its lower position, conductor 33 and thence to the line relay (not shown) associated with the signal 5.

This line relay associated with the signal 5 controls the circuit for the line relay 18 in the same way as the line relay 18 controls the line relay of the signal (not shown) to the left of the signal 4, that part of the. circuit for this latter line relay shown in Fig. 1 being along conductor 34, armature 14 of the track relay 1 1 in its upper position, conductors 35 and 36, armature 18 of the line relay 18 in its upper position, conductors 37, 38 and 39, secondary 22 of the transformer T conductors 10, ll, 28 and 27 to the common wire 26,

In other words, the conductor 33 of the circuit for controlling the line relay 18 corresponds to the conductor 35 for controlling the line relay of the signal to the left of the signal 4, and from the circuit for controlling this latter relay, it can be seen that the controlling circuit for the line relay 18 after passing through the armature 16 of the track relay 16 and the armature 21 of the stick relay 21 may be traced along conductor 33, through a front point of an armature of the line r'elay (not shown) associated with the signal 5, thence through the secondary of the transformer T and back to the common wire 26. From this with'thesignal 6. The line relay l9 'acts conjointlywith because of the de'energization of the line relay associated with the signal, if there he one, at the right oi the signal 5, said line rela' at the si nal will cause the deenergization of the line relay 18 at the signal 4, which line relay 18 in turn cause a deenergization of the line relay associated with the signal, if there be one, at the left of the signal 4. v

The armature of each line relay, as the armature 18 01 theline relay 18, which controls the circuit of the line relay for the signal in the rear is shunted when the corresponding stick relay, as the stick relay 20, is energized, this shunt in connection with the armature 18 being as follows: Commencing at the conductor 36, along conductor 42, armature 20 of the stick relay 20 in its upper position, and conductors 43 and 37. In this way when the stick relay 26 is energized, current may be supplied from the secondary 22 of the trans former T to conductor 34, leading to the line relay not shown) at the left of the signal 4, although the line relay 18 at the time is deenergized.

The controlling circuit for the line re- "lay 19 associated with the signal '7 is the same as the controlling circuit hereinbefore discussed for the line relay 18, that part of the controlling circuit for the line relay '19 which is-shown in Fig. lheing as follows: commencing at the common wire 26, conductors 88,89 and 44, relay 19, conductor 45, armature 16' of the track relay 16 in its upper position, conductor 46, arma true of the track relay 15 in its upper position, conductor 47', armature 20 of the stick relc y 20 in its lower position, conductor 48, and thencethrough a front point on an armature of the line relay associated the stick relay 21 to govern the controlling circuit of the line relay associated with '56 the signal (not shown) at the right of the SlPllZLl Tand governing trafiic 1n the same direction; hut since this shunt and controlling circuit is the same as that already described in connection with the line relay 18, no further description isnecessary;

7 is energized the c operating mechanism of the corresponding #Vhen each line relay 'sig ml is supplied with current which 0p erates the semaphore arm of the signal to its vertical pos1t1on,--as shown 1n the draw- 7 mg, and holds it in that position The op-V crating circuit. for the signal. '4 may be traced as follows: commencingat the right hand terminal of the secondary 22 of the transformer T conductors 39, 38, 37 and,

49, armature 18 of the line relay 18 in its 2 secondary .23 of the transformer T conductors 53, 54, and 56, armature 19 of the line relay- 19 in its upper position, conductor 57 operating mechanism of the signal 7, and conductors 58, 59 and 60, back to the other terminal'of said secondary 23.

As stated hereinbefore, thestickrelay as-v sociated with a signal is energized when a train 1s moving in the direction of traffic governed by that signal and passes said signal. The preliminary energizing or pick up circuit forthestickrelay 20 may be traced as follows: commencing at the right hand termmal ot the secondary'22 of the transformer T conductors-89 and 61, circuit' controller 24 of the signal 4 closed, condi1ctor-'62, armature 15 'oif' the track relay 715' in lower position,.- conductors 63 and 64,

its

stick relay 20, conductor 65, and thence either along conductor 66, armature 15* of the track relay 15 in either its lower or upper position, and conductors 67 01 68, 69, 52 and 40 to the other terminal of said secondary 22,01 from saidconductor 65 along conductor -70, armature 14 of the track relay 14 in 2 either its upper or lower position, conductor 71 or 72, and conductors 73, 28, 41 and 40 to the other terminal of said secondary 22.

The maintaining or stick circuit for the stick relay 20 may betraced as follows: com

mencing at the right hand terminal ofthe secondary of the transformer T conductors'39, 38, 37 and 49, armature 18 0f the line relay 18 in its lower position, conductor 74,-armature'20 in its upper posit-ion, conductors? 5 and 64, stick relay 20,-conductor 65, and thence through either :the armature 14 0f thetrack relay 14 or the armature 15 '01": the track relay 15, wheneitherfof saidarmatures are in either their upper or lower position, and back to the other termmal of the secondary 22 inthesame way asiabove described in connection with thejpick up circuit for the stick relay 20;

The pickup circuits for the stick relay 21 is the same in efl ect as that of the stick relay 20,and may be traced as follows: commenc-' mg at the right, hand terminal of'the sec 53,0ircu'it controller 2530f the signal 7 closed,

16 in its lower osition conductors 77 and ondary 23' of thetrans'former T conductor 78, stick relay 21,1co'ndnctor 79,and thence either along conductor 80, armaturezl'l of thetr'ack relay 1'? in either its upper or lower position, conductor 81 01382 and conductors" S3, 89, 90, 59'and 60,'back1 tothe'other ter operating them,

of these brackets designated iixed a rod ,bent up and has fastened thereto a piston minal of the secondary 23, or from said conductor 7 9 along conductor 8e, conductor 85 or 86, armature 16 of the track relay 16 in either its upper or lower position, and conductors 87 and 60 to the other terminal of said secondary 23.

The stick circuit for the stick relay may be traced as follows: commencing at the right hand terminal of the secondary 23 01 the transformer T conductors 53, and 56, armature 19 015 the line relay 19 1n its lower position, conductor 91,.arnature 21 of the stick relay 21 in its upper position, conductors 92 and 78, stick relay 21, conductor '7 9, and thence along conductor conductor 84 through either the armature 16 or the armature 17 in either the upper or lower .position, to the other terminal of the secondary 23 in the same way as above described for the pick up circuit of the stick relay 21.

The armatures 4 15 16- and 17 included in the pick up and stick up circuits for the stick relays 20 and 21 are indicated in Fig. 1 as provided with a suitable device, designated generally R, which device ,is designed to retard the upward movement of these armatures when the corresponding track relays have been deenergized and are renergized. The upward movement of these armatures may beretarded in various ways; but one simple means, consisting of a dash-pot attachment, is shown in Fig. 2

as applied to a relay of well known construc- The construction oi": the contact fingers manner of supporting and is like that shown in the patents to XV. K. Howe, 1,012,081 of December 19, 1911, and 1,019,047 of March 5th, 1912; and since the construction is fully described in these patents it will be necessary to refer only briefly to the construction of the parts as they are shown in Fig. 2. Reierring to 2, there is illustrated the usual contact carrying block 93 of suitable insulating material, which is supported by suitable brackets or arms, so as to be capable of oscillating on a horizontal axis, only one 94, is shown in Fig. 2; and fixed to the contact block 98 is an arm 95 to which is connected a link 96 tion. in this relay, the

.which serves to connect the arm 95 with a motor or other meansused for operating the relay. The contact carrier block 93 supports two contact fingers 97 and 98, one of which, 97, presses against the fixed contact pieces 99 when said contact finger 97 is in its upper position, while the other contact finger 98, when in its upper position, presses against a contact piece 100, and when in-its lower position, presses against a contact piece 101. To the contact finger 98 is rigidly 102, the lower end of which is 103including a flexible disk of leather or shown) to the similar material; and the piston 103 is arranged to move up and down in a dash-pot cylinder 10% fastened to some the rr ay, said dash-pot cylinder 10% having a small hole 105 therein in its upper end. The operation of the dash-pot attachment for the contact finger 98 will be readily apparent, it being obvious that the piston 103 may move downwardly in the dash-pot cylinder 104s with little opposition, but can move upwardly from its lower position, shown in Fig. 2, only as vfast as the air in said cylinder can escape through the small hole 105. In this way when the relay is deenergized and the arm 95 is raised to the position shown in Fig. 2, the contact finger 98 will be moved downwardly simultaneously with the contact finger 97, whereas, when the arm-95 is pulled to its lower position, thereby raising the contact finger 97, the contact finger 98 is retarded by the dashpot attachment and will assume its upper position, in which it presses against the contact piece 100, only after the lapse of ashort intervalof time dependent upon the adjustment ofthe dash-pot device.

As stated hereinbefore, the purpose ofthis invention is to prevent interference with the proper operation of the system by a tem porary interruption of the current supplied from a single source; but before considering the operation of the system under the par ticular conditions existing when the current supplied to the system is temporarily interrupted, it seems expedient to describe briefly the operation of the part of the system shown in the accompanying drawing under normal operating conditions, it being considered sufficient in view of the full illustration and description of the system in my prior application above mentioned, to describe in a general way the operation for a train moving in one direction only. Assuming the signals to 7 inclusive and their con-. trolling devices are in the position as shown in Fig. 1, suppose a to right, in the direction indicated by the arrow X, enters into the stretch of single track in which the track sections A, B, C and D form a part. This train movement causes all of the signals, including the signals 6 and 7 governing traiiic in the opposite direction, to assume their stop positions by reason of the successive deenergization of the line relays associated with these signals, and also causes the signal, governing traffic in the same direction in which the train is moving and protecting the track section now occupied by the train, to assume its stop position. Consider that this train advances until it occupies the track section A, then the dropping of the armature 14: of the track relay 14; interrupts the circuit leading from the conductor 34 to the line relay (not left of the signal 1 and govfixed part of train moving iror left erningtraffic in the same direction. As the is energized, sincelthesignal 4 is in its ,vertical' position and the circuit controller 24 closed, and since the armature of the track relay 15 drops. The dropping of the cuit for the line relay 18, thereby causing its armature 18 to assumeits lower position, whereby the stick circuit for the stick relay 7 is established. In this connection it :nal l and governing permitting said should be noted that the armatures 141 and 15 of thetrack relays 1st and 15, respectively, Whichare provided with the dash-pot attachment R are successively moved to their lower positions, so that one or the other of these armatures maintains the path from the stick relay to the left hand terminalof the secondary of thetransformer T In other Words While the train is in the track V section A, the armature 14 of the track relay 14;, being in its lower position, maintains the above mentioned path; and When the train enters the blockB the armature 15" drops unimpeded by the dash-pot attach ment and establishes another path for cur-- rent to fioiy from the stick relay 20 to the secondary 22, so that when thetrain leaves the track section A. and the armature 14 gradually assumes its upper position, the armature 15* being held in its lower position by the train on the track section B, maintains said conducting path, andby the time the train leaves the track section B, the armature 14 has assumed its upper position and maintains said conducting path While the armature 15 is gradually moving from its lower position to its upper position; In this Way the dash-pot attachment R to the armatures 1& and 15 does not interfere in any ay with the proper making of the pick up and stick up circuits of-the stick When the stick relay 20 is energized, its. armature 20 establishes the shunt hereinbefore traced for the armature 18 of the line relay 18, so that, although the track section is now occupied by thetrain and the'line relay 18 is deenergized, the line relay associated With the signal at the'left of the sigtrafiic in the same direction may be energized as soon as the train has entirely left the track section A, thereby signal to the left to assume an-operated position to permit another train to follow the first train. In a similar way the movement of the first train past the signal 5 permits thesignal l to assume a operated position, due to the picking up and the sticking up of the stick relay associated tvith the signal 5 a1'1dthe same operation occurs at, the s ares-sits si nals asserting traits rozn left" to right until the first train has leftthe' stretch of single" track. A similar operation occurs for atrain traveling in the direction indicated by the arrow and in this case the signals 5 and 4 are movedto their stop position, While, due to the energization of the stick relaysassociated With the signals 6' and 7, these signals'and other armature lo interrupts the controlling c1r- It should'be' noted that When the stick relay 20 is energized the armature 20 of this relay interrupts the controlling circuit h'erein'before traced for the line relay 19,

so that, While the stick relay 20 is errer gized, the line relay 19 must be 'deefiergi-zed.

One purpose of this control is to check the operation. of the stick relay 20, so that, if the armatures" of this stick relay for any reason fail to return to their lower position When this relay is deenergized, the opposing signal, namely the signal 7, Will be held in its stop position; In a; similar Way the controlling circuit for the line relay 18 associated With thesignal 4 is controlled by the armature 21 of the stick relay 21 associated with the signal 7 which signal 7 governs traffic in the oppositedirectioii.

To enable a clear understanding of the nature of the improvement embodying this invention, it Will be necessary" to explain the difi'iculty encountered in systems Wherein the current for operating the signals and 7 their controlling devices for a portion ofa railroad is derived from a single source, in case this supply of current is temporarily interrupted; and for this purpose assume that armatures 14. 15 16 and 17 ,together with their retardingdevice R, are omitted, and that the conductor 65 of the stick re-. lay 20 is directly connected to the left hand terminal of the secondary 22' of the transformer T and that the conductor 79' of the stick relay 21 is similarly directly connected tothe left hand terminal or the secordary 23 of the transformer T this direct connection being the same as that used in the signaling system disclosed in my prior application above mentioned; Suppose now that the snpplyof current to the different relays of thefsignaling system is temporarily lnterrupted, this being not an infrequent ee- 7 currence Where an alternating current transm1ss1on line is used, since the requirements of operation, such as tral station, somet mes result in the-power being taken from the transmission line for avery short time. When the current supplied to the different relays is'first cutofi' drop and V the armamres of all these relays the semaphore of the different signals gradually move tovvlard their biased orswitching at the cencurrent is very brief and that the semaphore arm of asignal, as for instance the signal 4:, is not moved far enough toward its horizontal position to open the circuit controller, as the circuit controller 2%, governed by that signal, before the, current is reapplied. Under these conditions the pick up circuit for the difi erent stick relays is closed, for the reason that, referring to the stick relay 20, the armature 15 is in its lower position and the circuit controller 2 is still closed. Although the reapplying of the current reenergizes the track relay 15 and immediately causes the armature 15 of this relay to move from its lower position, the armatures oi the stick relay 20 are simultaneously moved, and it is possible, and in fact in practice a likely occurrence, for the armatures of the stick relay 20 to be raised to their upper position. When the armature 20? of relay 20 is raised, it opens a break in the controlling circuit for the line relay 19, so that this line relay will remain deenergized; and-in a similar way the armature 21 of the stick relay 21, when raised, interrupts the controlling circuit for the, line relay 18 and maintains that line relay deenergized. As pointed out, the stick re lays 20 and 21, if the interruption of the supply of current is only brief, will be both energized, and it can be readily seen that the energization of both of these stick relays results in a deenergization of both of the line relays 18 and 19; and since the armature 18 of the line relay 18 is in its lower position, the stick circuit for the stick relay 20 is established, and similarly since the armature 19 of the line relay 19 is in its lower position, the stick circuit for the stick relay 21 is established. .In short, it the cessation ofcurrent is of the right duration it is possible for both of the stick relays 20 and 21 to be stuck up and this results in the two opposing signals l and 7 being both placed in the horizontal or stop position and remaining there, thereby seriously interfering with the movement or traflic.

The difiiculty above described is, however, obviated by the use of the armatures 1& 15 16 and 17 and some device such as illustrated in Fig. 2 for retarding the upward or pickup movement of these armatures. It has already been seen that these armatures and the retarding attachment do not affect the normal operation of the system; but in case there is atemporary interruption in the supply of current, the action of these armatures is such as to obviate the difliculty above described. To illustrate, assume similar conditions to those above assumed, that is, that the current is temporarily out oft", but is reapplied before the semaphore arms of the signal which'are spectively, move upward the stick governed by said in the vertical position move far enough to ward their horizontal position to-open the circuit controllersgoverned thereby. Referring to the stick relay 20, when" the current is first reapplied the armatures' 15 14: and 15 are in their lower position and, consequently, the pick up circuit for the stick relay 20 is temporarily established as before; but shortly after the current. is reapplied to the track relays 141: and 15, the armatures 14: and lo -of these track relays. reenough to breakcontact with the conductors 7 2 and 68, respectively, thereby interrupting both the pick up circuit and the stick up circuit for the stick relay 20. The dash-pot attach- 3611i}; for the armatures 14: and 15 are preferably so adjusted that before these armatures rise enough to. make contact with conductors 71 67, respectively sullici-mt time will have elapsed for the armatures oi the stick relay 20 to drop. In this way the pick up circuit for the stick relay 20, which is initially established, is broken at armature 15 and the stick circuit for said stick relay 20 is broken at the armature- 20 with the result that the stick relay 20 will not be improperly picked up by the temporary cessation of the current.

7 Although I have particularly described the construction of one physical embodiment of my invention, and, explained the operation and principle thereof; nevertheless, I desire to have it understood that the term selected is merely illustrative, but does not exhaust the possible physical embodiments of the idea of means underlying my invention. I

V] hat I claim as new and desire to secure lay Letters Patent of the United States, is 1- 1. In a signaling system for railroads, in combination: a stretch of track divided into track circuit sections; a first signal and a second signaljtor governing trafiic in opposite directions over said stretch; a controlline circuit for oachsignal; a stick relay associated with each signal; means controlled by each stick relay for interrupting the controlling circuit for the opposing signal when that stick relay is energizedpa pick up circuit for each relay; a stick circuit for each stick relay; and means governed by the tILCJ circuits of two track sections adjacent to each signal {For temporarily interrupting both the pick up circuit and the stick up circuit for the corresponding stick relay when said track circuits are si-" multaneously reenergized.

2. In a signaling system for railroads, in combination: a stretch of track divided into track circuit sections; a signal for governing trafiic-over said stretch; a circuit controller signal and closed when a portion of said stretch of track governed by that signal is not occupied, said circuit controller temporarily remaining'in its closed position after said portion of track. is occu pied; a stick relay; a pickup circuit for. said relay including said circuit controller andgoverned by a track'circuit section "adjacent to. said signal; a stickcircuit for said stick relay controlled by the relay itself and by the track circuit sections of the portion of track protected by said signal; means governed by the track circuits of. two track sections adjacent to said.v signal for temporarily interrupting both said pick up circuit and said stick up circuit when said track" sections are snnnltaneousiy reenerglzed; and means for slgnal ng controlled by sald stick relay. V

3. Ina signalingsystem for railroads, in combination: a stretch of track divided into track circuit sections; a stick relay governed by the track circuits of a portion of said stretch'of track; means for prehn-nnarlly energizing said'stick relayby the movement of a: train in one direction over said portion of track; means for maintaining said relay energized after it has been initially ,en

ergizedand so long as said portion of track is occupied; and means governed by two track circuits of said portionwof track for rendering said last mentioned means temporarily ineffective when these two track circuits are imultaneously reenergized.

at. In a signaling system for railroads, in combination: a stretch of single track divided into track circuit sections; signals for governing trafiic in opposite directions over,

a portion of said stretch; a controlling circuit for each signal which is governed by thetrack circuits of the track sections protected thereby; stick relay associated with each signal; means controlled by each stick relay for interrupting the controlling circuit for the other signal when that stick relay is energized; a stick circuit for each relay governed by the controlling circuit of the correspond ing signal; 'a pickup circuit for each relay controlled by some of said track circuit sections; a common source of current forv said circuits including the track circuits; and means for temporarily preventing energization of said relays upon resumption of the supply of current from said source after an interruption. Y

5. In a signaling system for railroads, divided into track sections provided with normally closed track circuits supplied with current from a common ource, the combina tion with anormally deenergized stick relay, ofa governing circuit for said relay controlled by some of said track clrcults, and

.means normally inactive when current is continuously supplied from said source for causing a temporary interruption; in send circuit when the supply of current from the a normally deenergized said. source is established after an ihterrup: tion. a r l 6. In a signalingsystem for railroads, di 7 vided into track sections provided with normally closed track circuits and having a common source of current for its circuits including the track circuits, the combina-.

tion With. a normally 'deenergized 7 stick relay, of an energizing circuit for said relay,

means including a slow acting normally c closed circuit controller for governing said energizing circuit, v and -means for temporarily preventing energization of saldr relay when the supply of current from said source is established after anfinterruption. r

7 In asignalingsystemifor railroads, divided into track sections provided with nor nally closed track circuits and having a common source oi": current for its circuits including the track circuits, thebombina'tion with a stick relay, of controlling circuits for initiating and maintaining a change in the condltlon of said relay,fand means con-' trolled by two adjacent track circuits for temporarily rendering said controlling cir cuits ineii ective when the track relays of said track circuits are simultaneously reenergized. V r

8. Ina signaling system for railroads, divided into track sections provided with nor mally closed track circuitsandhaving a common sourceof current for its-circuits. in-I eluding the track c1rcu1ts, the comblnatlon with a stick relay, of a controlling circuit for said relay lncludlng two branches in multiple, a slow-acting circuit controller included in each branch, said circuit con trollersz being governed separately by the track relaysof two adjacent track circuits and, being closed when the corresponding track relay is either energized or deenergized, whereby the continuity of the controlling circuit for said relay is maintained at one or the other of said circuit controllers durlng the normal operation of the track I relays in a sequence bya train moving over the track, but is interrupted when' said track relays are simultaneously 'reenergized.

9. In a signaling system for railroads, thecombihation with two adjacent track circuit sections each having a track relay rent from said source after an interruption.

10. In a. signaling system for railroads having normally closed track circuits and a common source of current for its circuits including the track circuits, the combination with two electrically operable devices at different points along the track controlled by certain track circuits, controlling circuits for each device for causing that device to be automatically changed from its normal condition by a predetermined operation of the track relays of its controlling track circuits, said devices being normally operated by train movements in opposite directions at different times and having their controlling circuits inter-connected to prevent the operation of either device when the other is in its changed condition, and means associated with each device for preventing a change in the condition thereof when its controlling track circuits are simultaneously renergized by a resumption of the flow of current fro said source after an interruption.

11. In a signaling system for railroads, having a track divided into track circuit sections each provided with a normally closed track circuit, the combination with signals for governing traflic in opposite directions, a controlling circuit for each signal governed by the track circuits of the track sections protected thereby, a normally deenergized stick relay associated with each signal, means controlled by each stick relay for interrupting the controlling circuit for the other signal when that stick relay is energized, a stick circuit for each stick relay governed by the controlling circuit of the corresponding signal, an energizing circuit for each stick relay including a slow-acting normally closed circuit controller governed by the controlling circuit of the correspondtrack circuitsafter an interruption.

12. In a signaling system for railroads,

having a track divided into track circuit sections each provided with a normally closed track circuit, the combination with signals for governing traflic in opposite directions, a controlling circuit for each signal governed by the track circuits of the track sections protected thereby, a normally deenergized stick relay associated with each signal, means controlled by each stick relay for interrupting the controlling circuit for the other signal when that stick relay is energized, a stick circuit for each stick relay governed by the controlling circuit of the corresponding signal, an energizing circuit for each stick relay including a slow-acting normally closed circuit controller governed by the controlling circuit of the corresponding signal, a common source of current for said circuits including the track circuits, the stick circuit and energizing circuit of each stick relay including two common branches in multiple, and a slowacting circuit controlling means included in each branch, said circuit controlling means being governed separately by two adjacent track circuits and being closed when the corresponding track relay is either energized or deenergized.

SEDGWICK N. WIGHT. 

